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In-Reply-To: <1d84bc01-fece-df55-6e33-07a705cfb432@huawei.com>
From:   Daeho Jeong <daeho43@gmail.com>
Date:   Wed, 15 Jul 2020 19:25:13 +0900
Message-ID: <CACOAw_xaS7qB22EPsZvHoC=uPiPtqGMAK5cP4Vk20xO21GQ-Kg@mail.gmail.com>
Subject: Re: [f2fs-dev] [PATCH v2] f2fs: change the way of handling range.len
 in F2FS_IOC_SEC_TRIM_FILE
To:     Chao Yu <yuchao0@huawei.com>
Cc:     Jaegeuk Kim <jaegeuk@kernel.org>,
        Daeho Jeong <daehojeong@google.com>, kernel-team@android.com,
        linux-kernel@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net
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Chao,

I can't find fscrypt_zeroout_range_inline_crypt() function. Do you
mean we need to implement this one for inline encryption?

2020=EB=85=84 7=EC=9B=94 15=EC=9D=BC (=EC=88=98) =EC=98=A4=ED=9B=84 4:17, C=
hao Yu <yuchao0@huawei.com>=EB=8B=98=EC=9D=B4 =EC=9E=91=EC=84=B1:
>
> On 2020/7/15 14:54, Daeho Jeong wrote:
> > You mean we can support ZEROOUT option only for encrypted files of
> > non-multidevice f2fs,
> > and return -EOPNOTSUPP in the multidevice case, right now?
>
> Yes, something like:
>
> f2fs_sec_trim_file()
>
> if ((range.flags & F2FS_TRIM_FILE_ZEROOUT) &&
>         f2fs_encrypted_file() && f2fs_is_multi_device())
>         return -EOPNOTSUPP;
>
>
> f2fs_secure_erase()
>
> if (!ret && (flags & F2FS_TRIM_FILE_ZEROOUT)) {
>         if (f2fs_encrypted_file()) {
>                 if (fscrypt_inode_uses_fs_layer_crypto)
>                         ret =3D fscrypt_zeroout_range();
>                 else
>                         ret =3D fscrypt_zeroout_range_inline_crypt();
>         } else {
>                 ret =3D blkdev_issue_zeroout();
>         }
> }
>
> Thanks,
>
> >
> > 2020=EB=85=84 7=EC=9B=94 15=EC=9D=BC (=EC=88=98) =EC=98=A4=ED=9B=84 3:1=
7, Chao Yu <yuchao0@huawei.com>=EB=8B=98=EC=9D=B4 =EC=9E=91=EC=84=B1:
> >>
> >> On 2020/7/15 12:06, Daeho Jeong wrote:
> >>> We could use fscrypt_zeroout_range() for an encrypted file.
> >>> But, one problem is fscrypt_zeroout_range() assumes that filesystems
> >>> only use a single block device.
> >>> It means it doesn't receive bdev as a parameter.
> >>> How about changing the interface of fscrypt_zeroout_range() first and=
 using it?
> >>
> >> Yes, please limited to use fscrypt_zeroout_range() on non-multidevice =
f2fs image
> >> first, we can add a condition to check that in the beginning of ioctl =
interface,
> >> once fscrypt_zeroout_range() accepts bdev as parameter, we can remove =
that limitation.
> >>
> >> Thanks,
> >>
> >>>
> >>> 2020=EB=85=84 7=EC=9B=94 14=EC=9D=BC (=ED=99=94) =EC=98=A4=ED=9B=84 9=
:36, Chao Yu <yuchao0@huawei.com>=EB=8B=98=EC=9D=B4 =EC=9E=91=EC=84=B1:
> >>>>
> >>>> On 2020/7/14 2:11, Jaegeuk Kim wrote:
> >>>>> Hi Daeho,
> >>>>>
> >>>>> Please take a look at this.
> >>>>>
> >>>>> https://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git/co=
mmit/?h=3Ddev&id=3D35245180459aebf6d70fde88a538f0400a794aa6
> >>>>
> >>>> I'm curious about what will happen if we call
> >>>> sec_trim_file(F2FS_TRIM_FILE_ZEROOUT) on an encrypted file, will
> >>>> it use zero bits covering encrypted data on disk?
> >>>>
> >>>> Thanks,
> >>>>
> >>>>>
> >>>>> Thanks,
> >>>>>
> >>>>> On 07/13, Daeho Jeong wrote:
> >>>>>> From: Daeho Jeong <daehojeong@google.com>
> >>>>>>
> >>>>>> Changed the way of handling range.len of F2FS_IOC_SEC_TRIM_FILE.
> >>>>>>  1. Added -1 value support for range.len to secure trim the whole =
blocks
> >>>>>>     starting from range.start regardless of i_size.
> >>>>>>  2. If the end of the range passes over the end of file, it means =
until
> >>>>>>     the end of file (i_size).
> >>>>>>  3. ignored the case of that range.len is zero to prevent the func=
tion
> >>>>>>     from making end_addr zero and triggering different behaviour o=
f
> >>>>>>     the function.
> >>>>>>
> >>>>>> Signed-off-by: Daeho Jeong <daehojeong@google.com>
> >>>>>> ---
> >>>>>> Changes in v2:
> >>>>>>  - Changed -1 range.len option to mean the whole blocks starting f=
rom
> >>>>>>    range.start regardless of i_size
> >>>>>> ---
> >>>>>>  fs/f2fs/file.c | 23 ++++++++++++-----------
> >>>>>>  1 file changed, 12 insertions(+), 11 deletions(-)
> >>>>>>
> >>>>>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> >>>>>> index 368c80f8e2a1..2485841e3b2d 100644
> >>>>>> --- a/fs/f2fs/file.c
> >>>>>> +++ b/fs/f2fs/file.c
> >>>>>> @@ -3792,7 +3792,7 @@ static int f2fs_sec_trim_file(struct file *f=
ilp, unsigned long arg)
> >>>>>>      pgoff_t index, pg_end;
> >>>>>>      block_t prev_block =3D 0, len =3D 0;
> >>>>>>      loff_t end_addr;
> >>>>>> -    bool to_end;
> >>>>>> +    bool to_end =3D false;
> >>>>>>      int ret =3D 0;
> >>>>>>
> >>>>>>      if (!(filp->f_mode & FMODE_WRITE))
> >>>>>> @@ -3813,23 +3813,23 @@ static int f2fs_sec_trim_file(struct file =
*filp, unsigned long arg)
> >>>>>>      file_start_write(filp);
> >>>>>>      inode_lock(inode);
> >>>>>>
> >>>>>> -    if (f2fs_is_atomic_file(inode) || f2fs_compressed_file(inode)=
) {
> >>>>>> +    if (f2fs_is_atomic_file(inode) || f2fs_compressed_file(inode)=
 ||
> >>>>>> +                    range.start >=3D inode->i_size) {
> >>>>>>              ret =3D -EINVAL;
> >>>>>>              goto err;
> >>>>>>      }
> >>>>>>
> >>>>>> -    if (range.start >=3D inode->i_size) {
> >>>>>> -            ret =3D -EINVAL;
> >>>>>> +    if (range.len =3D=3D 0)
> >>>>>>              goto err;
> >>>>>> -    }
> >>>>>>
> >>>>>> -    if (inode->i_size - range.start < range.len) {
> >>>>>> -            ret =3D -E2BIG;
> >>>>>> -            goto err;
> >>>>>> +    if (inode->i_size - range.start > range.len) {
> >>>>>> +            end_addr =3D range.start + range.len;
> >>>>>> +    } else {
> >>>>>> +            end_addr =3D range.len =3D=3D (u64)-1 ?
> >>>>>> +                    sbi->sb->s_maxbytes : inode->i_size;
> >>>>>> +            to_end =3D true;
> >>>>>>      }
> >>>>>> -    end_addr =3D range.start + range.len;
> >>>>>>
> >>>>>> -    to_end =3D (end_addr =3D=3D inode->i_size);
> >>>>>>      if (!IS_ALIGNED(range.start, F2FS_BLKSIZE) ||
> >>>>>>                      (!to_end && !IS_ALIGNED(end_addr, F2FS_BLKSIZ=
E))) {
> >>>>>>              ret =3D -EINVAL;
> >>>>>> @@ -3846,7 +3846,8 @@ static int f2fs_sec_trim_file(struct file *f=
ilp, unsigned long arg)
> >>>>>>      down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
> >>>>>>      down_write(&F2FS_I(inode)->i_mmap_sem);
> >>>>>>
> >>>>>> -    ret =3D filemap_write_and_wait_range(mapping, range.start, en=
d_addr - 1);
> >>>>>> +    ret =3D filemap_write_and_wait_range(mapping, range.start,
> >>>>>> +                    to_end ? LLONG_MAX : end_addr - 1);
> >>>>>>      if (ret)
> >>>>>>              goto out;
> >>>>>>
> >>>>>> --
> >>>>>> 2.27.0.383.g050319c2ae-goog
> >>>>>
> >>>>>
> >>>>> _______________________________________________
> >>>>> Linux-f2fs-devel mailing list
> >>>>> Linux-f2fs-devel@lists.sourceforge.net
> >>>>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> >>>>> .
> >>>>>
> >>> .
> >>>
> > .
> >